Field of the Invention
The present invention relates to a control apparatus and a control method.
Description of the Related Art
In recent years, optical coherence tomography OCT) and a scanning laser opthalmoscope (SLO) are being developed in the field of ophthalmologic apparatuses for imaging optical characteristics and movement of a fundus tissue of the eye.
A polarization-sensitive OCT and a polarization-sensitive SLO, which are examples of the OCT and the SLO, perform imaging using polarization parameters (i.e., retardation and orientation) that are optical characteristics of the fundus tissue.
For example, the polarization-sensitive OCT uses the polarization parameter to generate a polarization-sensitive OCT image and distinguish and perform segmentation of the fundus tissue. International Publication No. WO 2010/122118 A1 discusses employing a light beam that has been modulated to a circularly-polarized beam as a measuring beam for examining the sample. Detection is then performed by splitting the interference beam into two linearly-polarized beams perpendicular to each other, so that the polarization-sensitive OCT image is generated.
However, the apparatus discussed in International Publication No. WO 2010/122118 A1 cannot perform calibration in the case where a polarization state changes along with usage of the apparatus.